Marketing Of Unproven Genetic Tests A Threat To Public Health Apr 9, 2008
The authors reviewed claims made by testing businesses about the value of genetic testing for variability in cytochrome P-450 (CYP450) enzymes in predicting how individuals will metabolize antidepressants called selective serotonin reuptake inhibitors (SSRIs). At least 15 businesses currently offer CYP450 genotyping services, and four of those companies make specific claims that a CYP450 test can be used to recommend treatment, drug choice, and dosage. (Science Daily)
Why are different breeds of dogs all considered the same species? Mar 6, 2008
Currently a small gene found in the mitochondrial DNA of our cells--the cytochrome oxidase subunit 1 gene--is most commonly used in identifying members of the kingdom Animalia; a huge database is already in place for many of the world's animals using this gene. Domestic animals fascinated Darwin and continue to enthrall those of us who own pets. (Scientific American)
Genetic Determinants of Response to Warfarin during Initial Anticoagulation Mar 6, 2008
Background Genetic variants of the enzyme that metabolizes warfarin, cytochrome P-450 2C9 (CYP2C9), and of a key pharmacologic target of warfarin, vitamin K epoxide reductase (VKORC1), contribute to differences in patients' responses to various warfarin doses, but the role of these variants during initial anticoagulation is not clear. Methods In 297 patients starting warfarin therapy, we assessed CYP2C9 genotypes (CYP2C9 *1, *2, and *3), VKORC1 haplotypes (designated A and non-A), clinical... (New England Journal of Medicine)
New Drug Targets For Preventing Cell Death Discovered Mar 1, 2008
Early in apoptosis, the mitochondria -- complex structures that supply energy to the cell -- divide into pieces, holes appear in their membranes and proteins such as cytochrome c leak out ... Mdivi-1 also blocked the process that punches holes in the mitochondrial membrane, preventing leakage of cytochrome c. The researchers found that this process could also be traced back to the effect of mdivi-1 on dynamin. (Science Daily)
Waters Expands Mass Spectrometry Boundaries with Introduction of Next- Generation, Upgradeable SYNAPT Platform Jan 22, 2008
" Additionally, the University of Leeds' Astbury Centre for Structural Molecular Biology has published the results of protein research conducted with its newly-acquired SYNAPT HDMS System in the Journal of the American Society of Mass Spectrometry. Researchers at Leeds describe the successful separation and analysis of various folded forms of the proteins cytochrome c and beta-2- microglobulin, an achievement the Ashcroft Laboratory hopes will lead to a more complete understanding of the... (PR Newswire)
Anadys Pharmaceuticals Announces Positive Results for ANA598 in Animal Model of Chronic Hepatitis C Virus Infection Jan 4, 2008
It exhibits good in vitro metabolic stability properties and does not significantly inhibit or induce cytochrome P450 enzymes. In vivo, ANA598 was well tolerated in 14-day dose range finding (DRF) animal toxicology studies. (PR Newswire)
Frog species hidden in the upper Amazon Dec 22, 2007
Clades are separated by 12% to 15% net corrected p-distance for cytochrome b, with comparatively low sequence divergence within clades. Clades marginally overlap in some geographic areas (e. (BioMed Central)
ARYx Therapeutics Provides Update on Product Development -- Reports Results for 2007 Third Quarter Dec 20, 2007
However, unlike cisapride, ATI-7505 is not dependent upon a rate-limiting cytochrome P450 enzyme in the liver for metabolism and therefore avoids the build-up of drug levels associated with cisapride s toxicities ... Unlike warfarin, which is dependent upon cytochrome P450 enzymes for metabolism, ATI-5923 avoids drug-drug interactions through its alternative metabolic pathway ... We believe the avoidance of cytochrome P450 metabolism will cause the dosing and response to ATI-5923 to be more... (BusinessWire)
Mice Predict The Effectiveness Of Orally Taken Drugs Nov 22, 2007
Journal reference: New models for understanding the role of cytochrome P450 3A in xenobiotic metabolism, Journal Of Clinical Investigation, November 2007. Adapted from materials provided by. (Science Daily)
New Nanoparticle Technique Captures Chemical Reactions In Single Living Cell With Amazing Clarity Nov 20, 2007
Cytochrome c, for instance, is a protein involved in cell metabolism and cell death that has several optical absorption peaks of around 550 nanometers ... The researchers came up with a novel solution to this problem by coupling biomolecules, the protein cytochrome c in this study, with tiny particles of gold measuring 20-30 nanometers long. The electrons on the surface of metal particles such as gold and silver are known to oscillate at specific frequencies in response to light, a phenomenon... (Science Daily)
At our best: Local musicians get honorable mention Nov 19, 2007
A small but significant decrease in HDL cholesterol levels was observed in the group that received vitamin E supplementation during the supplementation period but did not appear to be related to the cytochrome p450 enzyme system or cholesterol ester transfer protein. Further studies are needed to clarify the interaction and clinical implications. (Corvallis Gazette Times, OR)
Drug May Restore Memory With Alzheimer's Disease Nov 13, 2007
And since it does not affect with the cytochrome P450 enzyme system, investigators believe that SP-233 should cause no unanticipated interactions with other medications that Alzheimers patients are likely to be taking. Acting in the liver, the P450 enzymes are responsible for metabolizing and helping to eliminate drugs and other chemicals. (Newsmax)
Functional evolution of the vitamin D and pregnane X receptors Nov 13, 2007
In contrast, using cultured primary hepatocytes, only zebrafish showed evidence of PXR-mediated induction of enzyme expression, with increases in testosterone 6beta-hydroxylation activity (a measure of cytochrome P450 3A activity in other species) and flurbiprofen 4-hydroxylation activity (measure of cytochrome P450 2C activity) following exposure to known PXR activators. A separate assay in vivo using zebrafish demonstrated increased hepatic transcription of another PXR target, multidrug... (BioMed Central)
Medicinal importance of grapefruit juice and its interaction with various drugs Oct 31, 2007
It has however, been found to be an inhibitor of the intestinal cytochrome P - 450 3A4 system, which is responsible for the first pass metabolism of many drugs. The P - glycoprotein pump, found in the brush border of the intestinal wall which transports many of these cytochrome P - 450 3A4 substrates, has also been implicated to be inhibited by grapefruit juice. (Nutrition Journal)
Attenuation of NASH by stimulation of free fatty acid metabolism Oct 27, 2007
This pathway is dependent upon expression of the cytochrome enzymes CYPA410 and CYP4A14. Stimulation of these pathways either individually or collectively could help remove excess free fatty acids from the liver and diminish the occurrence of NASH.. (EurekAlert!)
Genetically engineered plants can clean up toxic soil Oct 18, 2007
The enzymes used to metabolize the contaminants are from a group called cytochrome P450 found in both plants and animals. Poplars have a lot of P450s, but for the time being, the scientists are conducting experiments inserting a gene that produces cytochrome P450 in mammalian livers, in this case the livers of rabbits. (TopNews)
Trees with rabbit genes accelerate cleaning of soil Oct 17, 2007
Poplars use an enzyme called cytochrome P450 to break down contaminants ... Mammalian cytochrome P450 has been used in the past to create GM plants that can detoxify herbicide-treated fields. (Guardian Unlimited)
Pollution-Busting Plants Oct 17, 2007
The researchers used a bacteria to insert the genetic code for this cytochrome isolated from rabbits into the genetic instructions of the hybrid aspen tree, which belongs to the poplar family ... Because the cytochrome P450 2E1 works on a variety of contaminants, it also boosted the tree's ability to absorb the chloroform left over after cleaning drinking water, the industrial solvent carbon tetrachloride and even vinyl chloride although the latter blackened the leaves of the young aspen... (Nature News Service)
Scientists ramp up ability of poplar plants to disarm toxic pollutants Oct 16, 2007
The enzymes used to metabolize the contaminants are from a group called cytochrome P450 found in both plants and animals ... In the meantime they are conducting experiments inserting a gene that produces cytochrome P450 in mammalian livers, in this case the livers of rabbits ... Poplar genes producing cytochrome P450 is expressed in all their cells, but not at the rates achieved by the transgenics. (EurekAlert!)
Suspended Animation: Fact or fiction? Oct 2, 2007
Hydrogen sulfide binds with iron in cytochrome enzymes, disrupting a critical step in a process called oxidative phosphorylation, in which oxygen is burned to produce energy in the form of a substance called ATP. By blocking oxygen from binding to the iron, hydrogen sulfide stops cellular respiration and energy production completely. When energy production is inhibited, body temperature and metabolic rate are severely reduced. (FirstScience.com)
Revealing The Workings Of 'Mother Nature's Blowtorch' Sep 22, 2007
Cytochrome b5 diagram ... The first, cytochrome P450, does the actual work, but only when it gets a boost from the second protein, cytochrome b5 ... Because part of cytochrome b5 sticks to the membrane, such separations involve breaking the molecule at the sticking point, which happens to be the part that controls its interaction with cytochrome P450. (Science Daily)
Zebrafish to shed light on human mitochondrial diseases Sep 14, 2007
COX deficiencies refer to a breakdown of cytochrome coxidase, an enzyme located in the mitochondrion of every cell. Mitochondria are crucial cellular workhorses that provide chemical energy. (EurekAlert!)
Anadys Pharmaceuticals Presents Preclinical Results on ANA598, a Non-Nucleoside Inhibitor of the NS5B Polymerase, at the 14th International Symposium on Hepatitis C Virus and Related Viruses Sep 12, 2007
It also does not significantly inhibit or induce cytochrome enzymes, indicating that the compound has a low likelihood of producing clinical drug-drug interactions. ANA598 was well tolerated in 14-day dose range finding (DRF) animal toxicology studies at all doses tested (1 to 1000mg/kg). (PR Newswire)
Study Puts 1 Alzheimer's Theory in Doubt Aug 21, 2007
In prior studies, examination of the brain cells of people with Alzheimer's found some defects in an enzyme produced by the cytochrome c oxidase (COX) gene, which is important for mitochondrial energy production. In addition, so-called "free radicals," which cause oxidative stress, are produced in the cell's mitochondria, Moraes noted. (Health-Finder)
Scientists show that mitochondrial DNA variants are linked to risk factors for type 2 diabetes Aug 11, 2007
One rat strain exhibited impaired glucose tolerance, reduced muscle glycogen synthesis, decreased skeletal muscle ATP (energy) levels, and decreased activity of an energy-producing enzyme called cytochrome c oxidase, when compared to the second rat strain. These metabolic characteristics are typical of diabetic individuals. (EurekAlert!)
Grapefruit Linked To Cancer Jul 21, 2007
They theorize that grapefruit raises the levels of estrogen in the body by reducing the amounts of a chemical in the blood called cytochrome P450 3A4 (CYP3A4) that metabolizes estrogen. As little as one quarter of a grapefruit raised estrogen levels in the blood. (Newsmax)
Bak Protein Sets Stressed Cells On Suicide Path, Researchers Show Jul 18, 2007
"Some of the same proteins, cytochrome c is the big one, are needed for daily mitochondrial function like making energy, but if they are released from the mitochondria, they activate a cell killing or apoptotic pathway," says Dr. Dong, referencing the contents that spill from punctured mitochondria. Looking at kidney cells and neurons in a Bak deficient mouse, they also showed that Bak and Bax need each other to successfully spawn cell suicide. (Science Daily)
Evolution favors protein mutational robustness in sufficiently large populations Jul 18, 2007
We neutrally evolve cytochrome P450 proteins under identical selection pressures and mutation rates in populations of different sizes, and show that proteins from the larger and thus more polymorphic population tend towards higher mutational robustness. Proteins from the larger population also evolve greater stability, a biophysical property that is known to enhance both mutational robustness and evolvability. (BioMed Central)
Grapefruit link to breast cancer Jul 17, 2007
Previous studies have shown that a molecule called cytochrome P450 3A4 (CYP3A4) is involved in metabolising oestrogen hormones. And grapefruit may boost blood oestrogen levels by inhibiting this molecule, allowing the hormones to build up. (BBC News -- Health)
Phenotype-genotype analysis of CYP2C19 in Colombian mestizo individuals Jul 11, 2007
Omeprazole is metabolized by the hepatic cytochrome P450 (CYP) 2C19 enzyme to 5-hydroxyomeprazole. CYP2C19 exhibits genetic polymorphisms responsible for the presence of poor metabolizers (PMs), intermediate metabolizers (IMs) and extensive metabolizers (EMs). (BioMed Central)
A curious coincidence: mosquito biodiversity and the limits of the Japanese encephalitis virus in Australasia Jun 29, 2007
We sequenced 538 bp of the mitochondrial DNA cytochrome oxidase I gene from 273 individuals collected from 43 localities in Australia and the southwest Pacific region to describe the phylogeography of Cx. annulirostris and its sister species Cx. (BioMed Central)
Echinacea's Fortunes Brighten Again as Cold Remedy Jun 28, 2007
"Of note, echinacea is a human cytochrome P450 3A4 enzyme inhibitor so the potential for drug interactions also needs to be assessed.". The authors reported they had no conflicts. (MedPage Today)
Barcodes and biodiversity monitoring Jun 14, 2007
Our analyses, based on the two commonly used mitochondrial genes cytochrome c oxidase I (the standard DNA barcode for animal species) and cytochrome b (a common species-level marker), suggest that both arrays and barcodes are capable of discriminating mammalian species with high accuracy ... As for DNA barcoding, our analyses show that both cytochrome c oxidase I and cytochrome b genes, and even smaller fragments of them (mini-barcodes) can successfully discriminate species in a wide variety of... (BioMed Central)
Deficient Apoptosis Jun 8, 2007
g. DNA damage) triggers the release of cytochrome c from the mitochondria (the energy powerhouse of the cell) ... As a result, when cells have suffered extensive DNA damage that is irreparable, the p53 molecule may also trigger the apoptotic pathway via the release of cytochrome c, to eliminate such cells from the population. (Suite101.com)
Roses & raspberries Jun 4, 2007
A rose to 13-year-old Justin Song of Carmel Valley who of the National Spelling Bee by passing a 25-word written test and then advancing through the competition by correctly spelling the words "hoodlum," "cytochrome" and "rissole." He won the San Diego County Bee in March. His downfall was the word "Belial," an Old Testament name that has come to signify the personification of worthlessness or wickedness. (North County Times)
Cells re-energize to come back from the brink of death Jun 2, 2007
During apoptosis, the membrane covering the cells mitochondria develop holes and leak a molecule called cytochrome c, which triggers the activity of enzymes called caspases ... Previous research has shown that cells that become cancerous lack caspase and other proteins needed to support apoptosis after MOMP releases cytochrome c. But this victory over death is short-lived if CICD is activated. (EurekAlert!)
Carmel Valley teen loses out at national spelling bee semifinals Jun 1, 2007
Justin had advanced to Thursday's televised rounds by passing a 25-word written test, then advancing through the competition by correctly spelling the words hoodlum, cytochrome and rissole. He competed last year, but was eliminated early. (North County Times)
Local speller eliminated Jun 1, 2007
Justin had advanced to Thursday's televised rounds, which began at 7 a.m. local time, by passing a 25-word written test, then correctly spelling the words hoodlum, cytochrome and rissole. He competed last year, but was eliminated early. (San Diego Union-Tribune)
San Diegan advances in Nat'l Spelling Bee May 31, 2007
Justin advanced past the quarterfinals by correctly spelling cytochrome, an iron-containing protein, and rissole, a pastry consisting of minced meat or fish. Wednesday morning, the spelling championship at the Grand Hyatt Washington began with 286 spellers, making it the largest national competition in its 80-year history. (San Diego Union-Tribune)
MNI researchers find a new role for mitochondria in cellular copper regulation May 2, 2007
Copper is required for the activity of a number of enzymes including cytochrome c oxidase (COX) in the mitochondria -the energy suppliers of the body. "Our study is the first to characterize an unexpected cell-signaling or messenger role for the two copper-carrying proteins, SCO1 and SCO2, which are necessary for the assembly of COX," says Shoubridge. (EurekAlert!)
Lessening Hot Flashes: Exploring The Role Of Genes, Obesity And Alcohol Apr 26, 2007
An earlier study by the same team had found that one of these genetic polymorphisms, in an estrogen metabolizing enzyme, cytochrome P450 1B1, was more common in women who reported higher-than-average frequency, intensity and duration of hot flashes. The new study tied the same genetic polymorphism to lower levels of an androgen known as DHEA-S, and to lower progesterone levels. (Science Daily)
Sea snails break the law Apr 25, 2007
They observed the developmental stages of each species and sequenced a gene called mitochondrial cytochrome oxidase I. Then, based on the differences in gene sequences, they used several different techniques to reconstruct family trees. Indeed, they found that motile, feeding larvae had been lost and re-gained in the same family group, which breaks Dollos law. (EurekAlert!)
Astex Grants Cytochrome P450 License to Glaxosmithkline Apr 24, 2007
CAMBRIDGE, April 24 /PRNewswire/ -- Astex Therapeutics today announced that it has granted a non-exclusive, worldwide license to its cytochrome P450 intellectual property to GlaxoSmithKline. Under the terms of the agreement, GlaxoSmithKline will pay an up-front fee to Astex in return for a license under Astex's portfolio of granted and pending cytochrome P450 patents ... "This agreement is another example of Astex's commitment to making its human cytochrome P450 technology available to other... (PR Newswire)
Need oxygen? Cells know how to spend and save Apr 6, 2007
In the mitochondria, the tiny powerhouses found in every cell, energy is produced by passing electrons through a series of relay stations called cytochromes until they eventually join with oxygen to form water. This final step is directed by the protein cytochrome coxidase, or COX for short. (EurekAlert!)
Did the Dino Die-Off Make Room for Mammals? Apr 4, 2007
For instance, the human version of cytochrome b, (according to Bininda-Emonds the most frequently sequenced mammalian gene, which is associated with electron transport in mitochondria) could be compared with its chimp counterpart. The number of changes in the two varieties of that particular gene (plus the other 65) between the two species could allow researchers to approximate a divergence time. (Scientific American)
Medical Researchers Find A Treatment For Porphyria Apr 2, 2007
The symptoms of this disease appear when there are anomalies in the production of heme, a basic substance for the synthesis of vital proteins such as hemoglobin, myoglobin and cytochrome. Among the problems that this disease causes, which until now have been incurable, are included internal neuropsychological disturbances and severe stomach pains. (Science Daily)
Cyprotex Extends Cloe(R) Screen Mechanism-Based Inhibition Service to Include 4 Additional Cytochrome P450 Isoforms Mar 29, 2007
MANCHESTER, England, March 29 /PRNewswire-FirstCall/ -- Today, (29th March), Cyprotex announces that it has enhanced its Cloe(R) Screen Mechanism-Based Inhibition service to include 4 additional cytochrome P450 (CYP450) isoforms. These new assays compliment the CYP3A4 isoform assay which was launched last year, and provide information on 5 of the major CYP450 isoforms which are of interest in drug discovery. (PR Newswire)
Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes Mar 24, 2007
To address the general issue of whether transposons mediate genomic changes in environment-adaptation genes, we scanned two alleles per each of the six xenobiotic-metabolizing Helicoverpa zea cytochrome P450 loci, including CYP6B8, CYP6B27, CYP321A1, CYP321A2, CYP9A12v3 and CYP9A14, for the presence of transposon insertions by genome walking and sequence analysis. We also scanned thirteen Drosophila melanogaster P450s genes for TE insertions by in silico mapping and literature search. (BioMed Central)
Researchers Create Artificial Enzyme That Mimics The Body's Internal Engine Mar 17, 2007
The protein cytochrome c oxidase (CcO) is the ultimate enzyme responsible for all aerobic life on Earth, from bacteria to people. It is also a crucial component of the cellular machinery that generates energy in our body. (Science Daily)
The legacy of Linnaeus Mar 15, 2007
Every plant and animal has a mitochondrial cytochrome oxidase I gene, and its sequence helps researchers assign that plant or animal to a given species, with some degree of certainty. The precise degree of the certainty obtained using this 'barcode' sequence is a matter of some debate, but such sequences are clearly useful to both taxonomists and those who use applied taxonomy. (Nature News Service)
Where's My Personalized Medicine? Mar 7, 2007
Cytochrome P450: Structure, Mechanism, and Biochemistry. "P450 enzymes make drugs more water soluble and easier to excrete. The pharmaceutical industry, after some costly misadventures, knows that this is an absolutely crucial factor in the dosing of drugs.". (Wired News)
Primitive Yeast Yields Secrets Of Human Cholesterol And Drug Metabolism Mar 1, 2007
The search for Dap1 began with the hunt for factors that influence the actions of a large family of enzymes called cytochrome P450 ... Collectively, our experiments suggest that Dap1 acts as a common regulator of cytochrome P450s in mammals, says Espenshade. (Science Daily)
Life's Bar Code: Genetic Tests Unveil 15 New Species of North American Birds Feb 26, 2007
By using a portion of one gene cytochrome c oxadase I (COI) contained in the energy-producing mitochondria of cells in all eukaryotic life, researchers can now distinguish between species that look identical because this particular stretch of DNA mutates frequently. "Mitochondria [are] a good place for mutation because there is a lot of damaging stuff produced just in the course of respiration," Hebert explains. (Scientific American)
Electrons Travel Through Proteins Like Urban Commuters Feb 6, 2007
"Having this rule book in place will let scientists pose some hard but interesting questions about evolutionary pressures on protein structures."Another payoff may be new insight for designing biologically based artificial systems that, for instance, can capture solar energy or make fertilizer from air," he added.For more than 50 years, theoreticians have been pondering the most likely itineraries that electrons follow through electron-transfer proteins, Beratan said. These proteins "are... (Science Daily)
Turning Green Gunk To Gold, Anti-cancer Gold Jan 10, 2007
This included characterization of an enzyme, cytochrome P450, that always introduces the epoxide in the desired beta configuration. Sherman, who is also the John G. Searle Professor of Medicinal Chemistry in the College of Pharmacy, believes that this approach will allow effective new cryptophycin analogs with low levels of side effects to be created for clinical trials. (Science Daily)
Berry Compound Thwarts Enzyme Linked To Cancer Jan 4, 2007
Recent research by Agricultural Research Service (ARS) scientists and cooperators has fortified the standing of pterostilbene, a berry and grape compound cited for its health benefits, as a cancer inhibitor. Using gas chromatography/mass spectrometry, chemist Agnes Rimando analyzes pterostilbene content in blueberries. (Science Daily)
Mouse Lemur Species Not Determined By Coat Color Jan 4, 2007
The team used analysis of a mitochondrial gene, cytochrome b, to test the genetic relationship of the lemurs on the basis of their coat colors. The lemurs they tested had three different coat colors and lived in different types of forest locations in southern Madagascar -- classic characteristics of separate nocturnal species. (Science Daily)
